TWI473376B - Power supply system and control method thereof - Google Patents

Description

Power supply system and control method thereof

The present invention relates to a power supply system, and more particularly to a power supply system having a plurality of power modules that are hot-swappable and connected in parallel, and which can prevent a power supply module from generating a return path and a surge current during hot plugging. Its control method.

In order to solve the harmonic current problem of the power supply system used for power conversion in electronic equipment, Power Factor Correction (PFC) is one of the most widely used methods, so most of the power supply of electronic equipment The supply system is composed of a power module having a power factor correction function, and the power module includes a power factor correction circuit, so that the electric energy received by the electronic device, for example, the current distribution of the alternating current provided by the mains is not It will be too concentrated, produce less harmonics, and reduce unnecessary losses of electrical energy in electronic equipment.

With the continuous improvement of the power level of the electronic device and the demand for the backup function, at least two or more power modules are currently used to form the power supply system, wherein the output terminals of the power modules are connected in parallel and electrically Connected to the main circuit in the electronic device, so that the electronic device can get enough power to operate. What's more, in order to enable any power module to perform the swapping operation when the electronic device is in operation without having to shut down the electronic device and the power supply system, the plurality of power modules of the power supply system can be hot swapped (hot Swappable) for power supply Within the system.

However, when a plurality of power modules are connected in parallel to the power supply system in a hot plug mode, two main problems will be encountered. One of the problems is that when a plurality of power supplies are respectively supplied to a plurality of power modes. In the case of group power, if the phase of the multiple power supplies is different or the voltage difference between the multiple power supplies is caused, any power module will be operated in the power supply system when it is plugged into the power supply system by hot plugging. The output current output by the other power module will flow into the power module that is being hot plugged into the power supply system, that is, the power module that is being hot plugged into the power supply system generates an unexpected The reflow path, in this way, will reduce the filtering effect of the EMI filter of one of the power modules, and cause the potential of one of the output side capacitors of the power module to be precharged too high.

Another problem is that when any power module is plugged into the power supply system by hot plugging and connected in parallel with the running power module, it is inserted into the power module of the power supply system by hot plugging. The voltage on one of the output side capacitors is still zero at the moment the power module is inserted, so that the voltage output from the power module being operated in the power supply system will be the output of the power module inserted into the power supply system. The side capacitor is charged, so that the output side capacitor of the power module that is being plugged into the power supply system by hot plugging will generate a great dv/dt change, thereby causing the output side capacitor to generate an inrush current. The power module may be damaged by the surge current.

In order to avoid the above-mentioned shortcomings, some power supply system designs currently include an isolation transformer having a plurality of primary windings and primary windings, wherein each primary winding is outputted from a corresponding power module. The electrical connection is made, and the secondary winding is electrically connected to the main circuit of the electronic device, so that The isolation transformer can isolate a plurality of power modules, thereby preventing an unintended return path and surge current when any power module is plugged into the power supply system by hot plugging. However, due to the large size of the isolation transformer, The size of the power supply system cannot be reduced. In addition, since the power supply system additionally provides an isolation transformer to transfer power, the isolation transformer will cause the power supply system to generate unnecessary loss when transmitting power, resulting in reduced efficiency of the power supply system. .

Therefore, how to develop a power supply system and a control method thereof that can improve the above-mentioned conventional technology are urgently needed to be solved by those skilled in the related art.

The main purpose of the present invention is to provide a power supply system and a control method thereof. The power supply system includes a plurality of power modules that are hot-swappable and connected in parallel, and each power module has two switches. One of the open contacts is electrically connected to the positive output end of the power module, and the other switch is electrically connected to the negative output end of the power module, so that each power module can be correspondingly controlled according to the set conditions. The operation of the two internal switches is solved in the power supply system when any power module is plugged into the power supply system in a hot plug manner and connected in parallel with the power module being operated in the power supply system. The operating power module will cause the power module that is being plugged into the power supply system in a hot-swappable manner to produce an unexpected return path and surge current.

In order to achieve the above objective, a broader aspect of the present invention provides a power supply system comprising: a first power module, hot plugged into a power supply system, and converting power of the first power source to the first positive a first voltage is output between the output end and the first negative output end, and includes a first power factor correction circuit, a first switch and a second switch, the first power factor correction circuit outputs a first voltage, and the first switch is electrically connected to the first Power factor correction circuit and Between the first positive output terminals, the second switch is electrically connected between the first power factor correction circuit and the first negative output terminal, and is electrically connected to the ground end; and the second power module is hot plugged into the power supply System, and converting the electrical energy of the second power source to output a second voltage between the second positive output terminal electrically connected to the first positive output terminal and the second negative output terminal electrically connected to the first negative output terminal, and including a second power factor correction circuit, a third switch, and a fourth switch, wherein the second power factor correction circuit outputs a second voltage, and the third switch is electrically connected between the second power factor correction circuit and the second positive output terminal, fourth The switch is electrically connected between the second power factor correction circuit and the second negative output terminal; wherein the first power source and the second power source are electrically connected to each other by a center line, and when the first power module is operated in the power supply system When the second power module is hot plugged into the power supply system, the first power module and the second power module respectively control the phase difference between the second switch and the fourth switch only between the first power source and the second power source. Or when the voltage difference is less than a set value, The second power module controls the third connection opening on the second voltage is greater than the first voltage is turned on.

In order to achieve the above object, another broad aspect of the present invention provides a control method for a power supply system, wherein the power supply system includes a first hot power module and a second power module, and the first power module The unit converts the electric energy of the first power source to output a first voltage between the first positive output end and the first negative output end, and includes a first power factor correction circuit, a first switch and a second switch, and the first power factor correction The circuit is configured to output a first voltage, the first switch is electrically connected between the first power factor correction circuit and the first positive output terminal, and the second switch is electrically connected between the first power factor correction circuit and the first negative output terminal, and Electrically connected to the grounding end, the second power module converts the electrical energy of the second power source to a second positive output terminal electrically connected to the first positive output terminal and a second negative output terminal electrically connected to the first negative output terminal And outputting a second voltage between the second power factor correction circuit, the third switch, and the fourth switch, wherein the second power factor correction circuit outputs the second voltage, The third switch is electrically connected between the second power factor correction circuit and the second positive output terminal, and the fourth switch is electrically connected between the second power factor correction circuit and the second negative output terminal, and the first power source and the second power source are centered The wires are electrically connected to each other, and the control method comprises the following steps: (a) when the first power module operates in the power supply system, and the second power module is continuously hot-swapped in the power supply system, the first power module And the second power module first determines whether the phase difference or the voltage difference between the first power source and the second power source is less than a set value; (b) when the determination result is yes, the first power module and the second power module Controlling the second switch and the fourth switch to be respectively turned on; (c) the second power module continues to determine whether the second voltage is greater than the first voltage; and (d) when the determination result is yes, the second power module controls The third switch is turned on.

1‧‧‧Power supply system

10‧‧‧First power module

100‧‧‧First power factor correction circuit

101‧‧‧First Control Unit

102‧‧‧First detection circuit

103‧‧‧First comparison circuit

104‧‧‧First rectifier circuit

105‧‧‧First current balancing circuit

11‧‧‧Second power module

110‧‧‧Second power factor correction circuit

111‧‧‧Second Control Unit

112‧‧‧Second detection circuit

113‧‧‧Second comparison circuit

114‧‧‧First rectifier circuit

115‧‧‧Second current balancing circuit

20‧‧‧First power supply

21‧‧‧second power supply

9‧‧‧Electronic equipment

90‧‧‧ main circuit

91‧‧‧DC/DC converter circuit

Vo‧‧‧ main output voltage

V1‧‧‧ first voltage

V2‧‧‧second voltage

Io‧‧‧ main output current

Cbus‧‧‧ busbar capacitor

C1‧‧‧First output side capacitor

C2‧‧‧second output side capacitor

T1‧‧‧ first positive output

T2‧‧‧ first negative output

T3‧‧‧ second positive output

T4‧‧‧ second negative output

G‧‧‧ Grounding terminal

Ln‧‧‧ center line

SW1~SW4‧‧‧first switch~fourth switch

S1~S6‧‧‧Power supply system control steps

FIG. 1 is a schematic diagram showing the circuit structure when the power supply system of the preferred embodiment of the present invention is disposed in an electronic device and electrically connected to one of the main circuits in the electronic device.

Figure 2-4: It is a structural schematic diagram of various possible implementations of any of the first to fourth switches shown in Figure 1.

Fig. 5: This is a variation of the power supply system shown in Fig. 1.

Fig. 6 is a flow chart showing the control method of the power supply system shown in Fig. 1.

Some exemplary embodiments embodying the features and advantages of the present invention are described in detail in the following description. It should be understood that the present invention can be varied in various aspects without departing from the scope of the present invention, and the description and illustration thereof are in essence described as Use, rather than structure, to limit the case.

Please refer to FIG. 1 , which is a schematic diagram of a circuit structure when the power supply system of the preferred embodiment of the present invention is disposed in an electronic device and electrically connected to one of the main circuits of the electronic device. As shown in FIG. 1, the power supply system 1 of the present embodiment is disposed in an electronic device 9 and electrically connected to a main circuit 90 in the electronic device 9, and the power supply system 1 is used to output one of the direct currents. The primary output voltage Vo and a primary output current Io to the primary circuit 90 operate to drive the primary circuit 90, wherein in some embodiments, the primary circuit 90 can be, but is not limited to, a bus capacitor Cbus and a DC/DC converter circuit 91. The busbar capacitor Cbus is connected across the input end of the main circuit 90 for filtering the main output voltage Vo, and the DC/DC conversion circuit 91 is electrically connected to the bus current Cbus for converting the filtered main output voltage Vo. DC power (not shown) at another voltage level.

The power supply system 1 includes a plurality of power modules that are hot-swappable and connected in parallel, and each power module is powered by a different power source. The power supply system 1 includes only a first power source. The module and a second power module are used to exemplify the technology of the present invention. Referring to FIG. 1 , in the embodiment, the power supply system 1 includes a first power module 10 and a second power module 11 , wherein the first power module 10 is hot swappable to the power supply. In the system 1, the input end of the first power module 10 is electrically connected to a first power source 20, and the first power module 10 is configured to convert the power provided by the first power source 20 to output the first voltage. V1, and the first power module 10 further includes a first positive output terminal T1, a first negative output terminal T2, a first power factor correction circuit 100, a first switch SW1, and a second switch SW2. The first positive output terminal T1 and the first negative output terminal T2 are electrically connected to the input end of the main circuit 90, so that the first power module 10 can be connected to the first negative output terminal T1 via the first positive output terminal T1. A voltage V1 is transmitted to the main circuit 90. The first power factor correction circuit 100 is configured to perform power factor correction, and can convert the power provided by the first power source 20 to output the first voltage V1. The first switch SW1 is connected in series between the first power factor correction circuit 100 and the first positive output terminal T1. The second switch SW2 is connected in series between the first power factor correction circuit 100 and the first negative output terminal T2, and one end of the second switch SW2 and the first negative output terminal T2 are electrically connected to a ground terminal G.

The second power module 11 is also hot-swappable in the power supply system 1 , and the input end of the second power module 11 is electrically connected to a second power source 21 , and the second power module 11 is used to The power provided by the power source 21 is converted to output the second voltage V2, and the second power source 21 further includes a second positive output terminal T3, a second negative output terminal T4, a second power factor correction circuit 110, and a second power source 21 The three switches SW3 and the fourth switch SW4. The second positive output terminal T3 and the second negative output terminal T4 are electrically connected to the input end of the main circuit 90, so that the second power module 11 can pass the second voltage through the second positive output terminal T3 and the second negative output terminal T4. V2 is transmitted to the main circuit 90. In addition, the second positive output terminal T3 is further electrically connected to the first positive output terminal T1, and the second negative output terminal T4 is electrically connected to the first negative output terminal T2, so that the first power module 10 is connected. And the output side of the second power module 11 is connected in parallel. The second power factor correction circuit 110 is configured to perform power factor correction, and can convert the power provided by the second power source 21 to output the second voltage V2. The third switch SW3 is connected in series between the second power factor correction circuit 110 and the second positive output terminal T3. The fourth switch SW4 is connected in series between the second power factor correction circuit 110 and the second negative output terminal T4, and the one end of the fourth switch SW4 and the second negative output terminal T4 are also electrically connected to the ground terminal G. Since the first negative output terminal T2 and the second negative output terminal T4 are electrically connected to the ground terminal G, the voltage on the first positive output terminal T1 is actually the first voltage V1, and the voltage on the second positive output terminal T3 is actually The upper is the second voltage V2.

In some embodiments, the first power source 20 and the second power source 21 are electrically connected by a center line Ln, and may be, but not limited to, two of the multi-phase power sources, and further, the first power source 20 and the second power source The 21 Series provides AC power. Furthermore, the first power factor correction circuit 100 further includes a first output side capacitor C1 connected across the output side of the first power factor correction circuit 100, and the second power factor correction circuit 110 also includes a second output side. The capacitor C2 is connected across the output side of the second power factor correction circuit 110.

The operation principle of the power supply system 1 of the present invention will be further explained below. Referring to FIG. 1 again, first, when there is only the first power module 10 in the power supply system 1, and the second power module 11 is disconnected from the power supply system 1, at this time, if the power supply system 1 starts In operation, the first power module 10 will operate correspondingly and receive the power of the first power source 20, and the first power module 10 will control the first switch SW1 and the second switch SW2 to be in an on state, so that the first power module 10 The first power factor correction circuit 100 can convert the power of the first power source 20 into the first voltage V1, and transmit the signal through the first switch SW1, the second switch SW2, the first positive output terminal T1 and the first negative output terminal T2. To the main circuit 90.

Once the power supply system 1 is operating and the first power module 10 is also operating, the second power module 11 originally pulled out of the power supply system 1 is hot-plugged into the power supply system 1 so that the second The power module 11 is electrically connected to the first positive output terminal T1 and the first negative output terminal T2 via the second positive output terminal T3 and the second negative output terminal T4, respectively, and is connected in parallel with the first power module 10, and When the power module 11 is electrically connected to the second power source 21 and receives the power provided by the second power source 21, the first power module 10 and the second power module 11 respectively control the second switch SW2 and the first The four switches SW4 are turned on only when the phase difference or voltage difference between the first power source 20 and the second power source 21 is less than a set value, so that even between the first power source 20 and the second power source 21 The phase difference or the voltage difference is greater than the set value, so that the output current (not shown) of the first power module 10 will be due to the first negative output terminal T2 of the first power module 10 and the second negative of the second power module 11 When the output terminal T4 is electrically connected to the grounding terminal G and is to be inserted into the second power module 11 in the power supply system 1 by hot plugging, the first power module 10 and the second power module 11 are at this time. The second switch SW2 and the fourth switch SW4 are controlled to be turned off according to the phase difference or the voltage difference between the first power source 20 and the second power source 21 being greater than the set value. Therefore, the output current of the first power module 10 cannot pass through the first A negative output terminal T2 flows into the second power module 11 , so that when the second power module 11 is hot plugged into the power supply system 1 and connected in parallel with the first power module 10, it can be avoided. An unexpected return path is generated in the second power module 11 to maintain the filtering effect of an EMI filter (not shown) in the second power module 11 while preventing the second power of the second power module 11 Because the potential of the second output side capacitor C2 of the correction circuit 110 is pre-predicted Case of excessive happen.

Moreover, the phase difference or voltage difference between the first power source 20 and the second power source 21 is less than a set value, so that the first power module 10 and the second power module 11 respectively control the second switch SW2 and the fourth switch SW4. After being turned on, the second power module 11 will continuously control the voltage of the third switch SW3 at the electrical connection between the third switch SW3 and the second power factor correction circuit 110, that is, the output of the second power factor correction circuit 110. The voltage V2 is greater than the voltage at the electrical connection between the third switch SW3 and the second positive output terminal T3, that is, the first power module 10 transmitted from the first switch SW1 and the first positive output terminal T1. When the first voltage V1 is turned on, in more detail, when the second power module 11 is inserted into the power supply system 1 in a hot plug manner and connected in parallel with the first power module 10, the second power source is used at this time. The power provided by 21 is still unable to make the level of the second voltage V2 on the second output side capacitor C2 larger than the first voltage output by the first power module 10 due to charging. When V1, the second electric module 11 controls the third switch SW3 to be turned off, thereby preventing the second output side capacitor C2 from generating a great dv/dt change due to the first voltage V1 output by the first power module 10. The generation of the surge current is prevented, and only when the power supplied by the second power source 21 continues to charge the second output side capacitor C2 such that the voltage level of the second voltage V2 is greater than the voltage level of the first voltage V1, the second The electric module 11 controls the third switch SW3 to be turned on, so that the second voltage V2 output by the second electric module 11 is transmitted to the main circuit 90.

In some embodiments, as shown in FIG. 1 , the first power module 10 further includes a first control unit 101 , and the first control unit 101 is electrically connected to the control ends of the first power source 20 and the second switch SW2 . The first detection circuit 102 is configured to detect the phase or voltage of the first power source 20, and the second power module 11 also includes a second control unit 111. The second control unit 111 is electrically connected to the second power source 21 and the fourth switch SW4, and has a second detecting circuit 112 for detecting the phase or voltage of the second power source 21, and the second detecting circuit 112 The first detecting unit 102 and the second detecting unit 111 can learn the detection result of each other by the first detecting unit 102 and the second detecting unit 112. Therefore, the first control unit 101 can know whether the phase difference or the voltage difference between the first power source 20 and the second power source 21 is smaller than the detection result of the first detecting circuit 102 and the second detecting circuit 112. Set the value, and then output the corresponding control signal (not shown) to control The second switch SW2 performs switching between on-off or off, and the second control unit 111 synchronizes between the first power source 20 and the second power source 21 according to the detection results of the first detection circuit 102 and the second detection circuit 112. Whether the phase difference or the voltage difference is less than a set value, and further outputting a corresponding control signal (not shown) to control the fourth switch SW4 to switch on or off, thereby being at the first power source When the module 10 or the second power module 11 is inserted into the power supply system 1 by hot plugging, an unexpected return path is prevented from occurring in the first power module 10 or the second power module 11.

In some embodiments, as shown in FIG. 1 , the first power module 10 further includes a first comparison circuit 103 connected across the first switch SW1 and opposite to the control end of the first switch SW1. The electrical connection is used to detect the voltage on the electrical connection between the first switch SW1 and the first power factor correction circuit 100, that is, whether the first voltage V1 output by the first power factor correction circuit 100 is greater than the first The voltage at the electrical connection between the switch SW1 and the first positive output terminal T1, that is, the voltage corresponding to the second voltage V2 of the second power module 11 transmitted from the third switch SW3 and the second positive output terminal T2 A control signal (not shown) is output to control the operation of the first switch SW1. The second power module 11 further includes a second comparison circuit 113 connected across the third switch SW3 and electrically connected to the control terminal of the third switch SW3 for detecting the third switch SW3. Whether the voltage at the electrical connection with the second power factor correction circuit 110, that is, the second voltage V2 output by the second power factor correction circuit 110 is greater than the electrical connection between the third switch SW3 and the second positive output terminal T2 The upper voltage, that is, the second voltage V1 of the first power module 10 transmitted from the first switch SW1 and the first positive output terminal T1, corresponds to an output control signal (not shown) to control the third The operation of the switch SW3.

In some embodiments, the first power module 10 further has a first rectifier circuit 104 electrically connected between the input end of the first power module 10 and the first power factor correction circuit 100. Rectification. The second power module 11 further has a second rectifying circuit 114 electrically connected between the input end of the second power module 11 and the second power factor correcting circuit 110 for rectification.

Please refer to Figures 2 to 4, which are the first to fourth switches shown in Figure 1. A schematic diagram of the structure of various possible implementations of a switch. In other embodiments, the first switch SW1 to the fourth switch SW4 may be respectively formed by a semiconductor power switch, for example, an N-type power MOSFET (N-type Power MosFET) shown in FIG. 2, respectively. , Power JFET shown in Figure 3, Back-to-back Power MosFETs shown in Figure 4, or the above three types of electricity The crystal is composed of one, but not limited to this.

In some embodiments, in order to make the output currents of the first power module 10 and the second power module 11 in the power supply system shown in FIG. 1 equal, as shown in FIG. 5, the first power module 10 The first current balancing circuit 105 is further provided with a second current balancing circuit 115. The first current balancing circuit 105 is connected across the second switch SW2. The second current balancing circuit 115 is further connected to the second current balancing circuit 115. The first current balancing circuit 105 and the second current balancing circuit 115 are connected to each other to communicate with each other, and the first current balancing circuit 105 and the second current balancing circuit 115 are respectively configured to detect The current flowing through the second switch SW2 and the fourth switch SW4, so that the first power module 10 and the second power module 11 adjust the output current according to the detection result, so that the first power module 10 and the second power module The output currents of group 11 are substantially equal.

Please refer to FIG. 6 and cooperate with FIG. 1 , wherein FIG. 6 is a schematic flow chart of the control method of the power supply system shown in FIG. 1 . As shown in FIGS. 1 and 6, first, in step S1, when the first power module 10 operates in the power supply system 1, and the second power module 11 is subsequently hot-swapped into the power supply system 1, the first The power module 10 and the second power module 11 first determine whether the phase difference or the voltage difference between the first power source 20 and the second power source 21 is less than a set value. When the result of the determination is yes, the process proceeds to step S2. First A power module 10 and a second power module 21 respectively control the second switch SW2 and the fourth switch SW4 to be turned on; otherwise, when the determination result is no, the process proceeds to step S5, that is, the first power module 10 and the second power mode. The group 21 controls the second switch SW2 and the fourth switch SW4 to be turned off, respectively.

After the end of step S2, the process proceeds to step S3, that is, the second power module 11 successively determines whether the second voltage V2 is greater than the first voltage V1. When the result of the determination is yes, the process proceeds to step S4, that is, the second power module. 11 controls the third switch SW3 to be turned on; otherwise, when the determination result is no, the process proceeds to step S6, that is, the second power module 11 controls the third switch SW3 to be turned off. In the above step S1, the first power module 10 controls the first switch SW1 to be continuously turned on.

In summary, the present invention provides a power supply system and a control method thereof, wherein a plurality of power modules in a power supply system are hot-swappable and connected in parallel, and a positive output of each power module and a negative The outlets are electrically connected to a switch, so that when any power module is hot plugged into the power supply system and connected in parallel with the running power module, all the power modules are only electrically connected to all the power modules. When the phase difference or the voltage difference between all the power sources is less than the set value, the switch that controls the electrical connection with the negative output terminal is turned on, and the power module that is hot-swapped to the power supply system and connected in parallel with the running power module is connected. When the voltage outputted by the power module is greater than the voltage outputted by the power module being operated, the switch that electrically connects to the power supply module of the power supply system is electrically connected to the positive output terminal, thereby power supply of the present invention. The system does not need to provide an additional isolation transformer to plug the power supply system into the power supply system and the power supply module in the power supply system. When connected in preventing hot-plug inserted in the power supply system of the power module generating the return path and are not intended to inrush current is generated, while the case of the power supply system of the body The product can be reduced and the efficiency of the power supply system can be increased.

This case has been modified by people who are familiar with the technology, but it is not intended to be protected by the scope of the patent application.

1‧‧‧Power supply system

10‧‧‧First power module

100‧‧‧First power factor correction circuit

101‧‧‧First Control Unit

102‧‧‧First detection circuit

103‧‧‧First comparison circuit

104‧‧‧First rectifier circuit

11‧‧‧Second power module

110‧‧‧Second power factor correction circuit

111‧‧‧Second Control Unit

112‧‧‧Second detection circuit

113‧‧‧Second comparison circuit

114‧‧‧First rectifier circuit

20‧‧‧First power supply

21‧‧‧second power supply

9‧‧‧Electronic equipment

90‧‧‧ main circuit

91‧‧‧DC/DC converter circuit

Vo‧‧‧ main output voltage

V1‧‧‧ first voltage

V2‧‧‧second voltage

Io‧‧‧ main output current

Cbus‧‧‧ busbar capacitor

C1‧‧‧First output side capacitor

C2‧‧‧second output side capacitor

T1‧‧‧ first positive output

T2‧‧‧ first negative output

T3‧‧‧ second positive output

T4‧‧‧ second negative output

G‧‧‧ Grounding terminal

Ln‧‧‧ center line

SW1~SW4‧‧‧first switch~fourth switch

Claims (12)

A power supply system includes: a first power module, hot plugged into the power supply system, and converting power of a first power source to output between a first positive output terminal and a first negative output terminal a first voltage, comprising a first power factor correction circuit, a first switch and a second switch, wherein the first power factor correction circuit outputs the first voltage, and the first switch is electrically connected to the first power Between the correction circuit and the first positive output terminal, the second switch is electrically connected between the first power factor correction circuit and the first negative output terminal, and is electrically connected to a ground end; and a second power source The module is hot-swapped to the power supply system, and converts power of a second power source to electrically connect one of the second positive output terminals and the first negative output terminal and the first positive output terminal a second voltage output is output between the second negative output terminal of the grounding terminal, and includes a second power factor correction circuit, a third switch, and a fourth switch, wherein the second power factor correction circuit outputs the a second voltage electrically connected to the second power factor Between the circuit and the second positive output terminal, the fourth switch is electrically connected between the second power factor correction circuit and the second negative output terminal; wherein the first power source and the second power source are connected to each other by a center line The first power module and the second power module are electrically connected when the first power module is operated in the power supply system and the second power module is hot plugged into the power supply system Firstly controlling the second switch and the fourth switch respectively, the phase difference or the voltage difference between the first power source and the second power source is less than a set value. When the current is turned on, the second power module continues to control the third switch to be turned on when the second voltage is greater than the first voltage. The power supply system of claim 1, wherein the power supply system is applied to an electronic device and is electrically connected to a main circuit of the electronic device for driving the main circuit to operate. The power supply system of claim 1, wherein the first power source and the second power source are two of the multi-phase power sources. The power supply system of claim 1, wherein the first power module operates in the power supply system and the second power module is hot plugged into the power supply system The power module and the second power module respectively control the second switch and the fourth switch to be turned off only when a phase difference or a voltage difference between the first power source and the second power source is greater than the set value. The second power module continues to control the third switch to be turned off when the second voltage is less than the first voltage. The power supply system of claim 1, wherein the first switch, the second switch, the third switch, and the fourth open relationship are respectively an N-type power MOS field effect transistor, A power junction field effect transistor or a back-to-back N-type power MOS field effect transistor. The power supply system of claim 1, wherein the first power module further includes a first control unit electrically connected to the first power source and the control end of the second switch, and has a first a detecting circuit, the first detecting circuit is configured to detect a phase or a voltage of the first power source, and the second power module further includes a second control unit, the second control unit is coupled to the second power source And the fourth switch is electrically connected, and has a second detecting circuit for detecting a phase or a voltage of the second power source, and is connected to the first detecting circuit signal The first control unit and the second control unit respectively determine the phase difference between the first power source and the second power source according to the detection results of the first detecting circuit and the second detecting circuit Or whether the voltage difference is less than the set value, and correspondingly controlling the actuation of the second switch and the fourth switch respectively. The power supply system of claim 1, wherein the second power module further includes a comparison circuit connected across the third switch and electrically connected to the control end of the third switch. And detecting whether the second voltage on one end of the third switch is greater than the first voltage on the other end of the third switch to correspondingly control the operation of the third switch. The power supply system of claim 1, wherein the first power module and the second power module are connected in parallel in the power supply system. A power supply system control method, wherein the power supply system includes a first power module that is hot-swappable and a second power module, wherein the first power module converts power of a first power source to a first positive output terminal and a first negative output terminal output a first voltage, and include a first power factor correction circuit, a first switch and a second switch, the first power factor correction circuit outputs the a first voltage electrically connected between the first power factor correction circuit and the first positive output terminal, the second switch being electrically connected to the first power factor correction circuit and the first negative output terminal And electrically connected to a ground terminal, wherein the second power module converts the power of the second power source to electrically connect the second positive output terminal and the first negative output to the first positive output terminal And outputting a second voltage between the terminal and the second negative output terminal of the ground connection, and comprising a second power factor correction circuit, a third switch and a fourth switch, wherein the second power factor correction circuit Outputting the second voltage, the third switch is electrically connected to the Two power factor correction Between the positive circuit and the second positive output terminal, the fourth switch is electrically connected between the second power factor correction circuit and the second negative output terminal, and the first power source and the second power source are connected to each other by a center line Electrical connection, the control method includes the following steps: (a) when the first power module operates in the power supply system, and the second power module is subsequently hot plugged into the power supply system, the first The power module and the second power module first determine whether a phase difference or a voltage difference between the first power source and the second power source is less than a set value; (b) when the determination result is yes, the first power module And the second power module controls the second switch and the fourth switch to be respectively turned on; (c) the second power module continues to determine whether the second voltage is greater than the first voltage; and (d) when the determination result is In this case, the second power module controls the third switch to be turned on. The control method of claim 9, wherein the step (a) further comprises the step (a1): when the determination result is no, the first power module and the second power module respectively control the The second switch and the fourth switch are turned off. The control method of claim 9, wherein the step (c) further comprises the step (c1): when the determination result is no, the second power module controls the third switch to be turned off. The control method of claim 9, wherein in the step (a), the first power module controls the first switch to be continuously turned on.